I have just finished an install of ubuntu 11.04 beta 2. At the end of the installation I got a message informing that I do not have the required hardware for unity, and that I should choose "ubuntu classic".

Could someone please shed some light on how to fix this? I have tried adding the "experimental 3d xyz" driver but still no luck. When I log out and try log back in there is no option for unity.

My graphics card is an nvidia 240gt or gt240, I cant remember now which way around it goes.

I enabled "experimental 3d support for nvidia cards" - this is what I was reffering to above, not a driver - sorry about that.

I have had problems with my nvidia card as well, and I think my answer to a similar question might help you. It list all my attempts (everything I found), plus what finally worked for me: adding nopat to the kernel parameters when booting. It is a known problem with nvidia cards.

Proprietary drivers in Ubuntu are drivers for your hardware devices that are not freely-available or open source, and must be obtained from the hardware manufacturer. The free and open source video driver, Nouveau, is the driver Ubuntu will use as the default for Nvidia graphics cards. Nouveau does not have support for 3D and may not work at all with latest video cards from Nvidia. Proprietary drivers, closed source, are the alternative for Nouveau, and most time provide superb 3D acceleration and overall video card support/performance. Follow these instructions to install proprietary drivers for your Nvidia Graphics Card.

I had this same issue, but none of the answers here fixed it for me. I eventually fixed it by doing this:

sudo modprobe nvidia

Which gave me a warning that nvidia_319 was actually blacklisted somehow...? So I did:

$ cd /etc/modprobe.d
$ sudo fgrep nvidia * | fgrep blacklist

which informed me that my earlier install of bumblebee was breaking the regular nvidia drivers. So I did:

$ sudo apt-get remove bumblebee
$ sudo rm bumblebee.conf

And that fixed the problem. If you have this problem, it may not be this exact issue with bumbleebee, but if your nvidia drivers are somehow blacklisted, this method will tell you what is blacklisting them and why, and you can attempt to deal with it that way. The "Additional Drivers" menu and jockey-text -l will not inform you that this could be a blacklist problem.

If the above or any of the other answers do not help, make sure that nouveau is blacklisted and then reinstall the nvidia drivers. Installing nvidia should do this for you, by making a file something like this (but if it doesn't, copy this one and make sure to blacklist all the drivers but the one you don't want to use)

You can check unity-2d as it will be the fallback environment from 11.10. As far as I understand, your graphics card does not meet unity 3d requirements which is the default desktop environment. You may try gnome classic desktop which is still available.